Sparking plug



Hl V, .L )OUFFRETg SPABKING PLUG.

APPLICATION FILED JUNE 10, 15H8. v I

UNITED STATES PWAENT OFFICE.

HENRI VICTOR JULES JOUF'FRET, `1? NEUILLY-SUB/-SIJINE FRANCE.

SPARKING PLUG.

Application filed June 10,

To all whom t may concern.

Be it known that I, HENRI Vieron J ULEs JoUFFnn'r, a citizen of the French Republic, residing at Neuilly-sur-Seine, Department of Seine, France, have invented certain new and useful Improvements in Sparking Plugs, o f which the following is a specification.

This invention relates to sparking plugs for internal combustion engines.

It has for its object the construction of devices ofthe class in uestion in such a way that their cooling is e ected in a more satisfactory and simple manner than it has hitherto been .the case.

The invention consists generally in combining with the ordinary insulated electrode of' the sparking plug, which `is preferably formed 'from a highly resisting metal such for instance as nickel steel, a metal which is a good conductor of heat.

The invention includes in addition to the principal constructional feature just mentioned, other features which will be described more `fully hereafter.

It also comprises certain constructional embodiments including the said features, and as new articles of manufacture, sparking plugs made with the said improvements, as well. as special parts lfor making up such A plugs.

In order that the invention may be clearly understood, I will now proceed to describe the same with reference to the accompanying drawing which is howevergiven merely by Way of example.

Figures 1 and 2 of the said drawing are axial sectional views of sparking plugs made according to two methods of carrying out the invention.

In constructing/,the sparking plug for in,- ternal combustion engines, as illustrated in the drawing, I provide, in the usual manner a metallic casing a, adapted to'constitute the electrode connected to the body of the engine and to be screwed to the cylinder ol the engine. I further provide an insulating body portion b adapted to be mounted in the said casing a. This may be made either' as shown at Fig. 1, where the insulated electrode is introduced from the end of the casing which is not screwed into the .cylinder of the motor, or else as shown in Flg. 2 where the insulated electrode is introduced through the extremity of the casing which screws Specification of Letters Patent.

Patented Feb. 8, -1921.

191s. serial no. 232,251.

into the motor cylinder, that is in one piece in the first case and in two pieces in the second.

4The insulator t is provided with a central hole for. the reception of the insulated electrode c.

In addition to, adopting the foregoing construction, according to myiinvention, I

provide for the insulated electrode c, a rod' said rod c a screw thread corresponding with an internal screw thread on the said sleeve c2. l

I mount the insulator b on the rod c in the ordinary way and then I place the sleeve 02 in position.

I thus obtain a sparking plug with which the insulated electrode and the insulator are mounted in the casing a in one of the ordinary methods, but with which the cooling is insured by the conductivity of the metal insei-ted into the hole o1 and by that of the sleeve c2.

In addition, I prefer to make the sleeve c2 of such length that it projects beyond the insulator and to provide fins c2 upon the projecting portion to assist the cooling.

A nut d serving to hold the electrode in the insulator also serves to keep the sleeve c2 in position.

It will be understood that the particular methods of carrying out the invention just described may be varied and that the invention is only limited by a fair interpretation of my claims. 

